The present invention relates to a high voltage measurement and, more particularly, to a high voltage detector that can be used for measuring voltages in high voltage alternating current (AC) circuits or systems with improved accuracy.
A voltage detector is a form of voltmeter that measures voltages without the use of a ground lead. The ground lead is avoided in situations where it would present a severe safety risk to the operator of the voltage detector. Typically, voltage detectors are used by those measuring high AC voltages such as electrical power utility linemen. Before the present invention, designers of voltage detectors assumed that the magnitude of the alternating current being measured by a voltage detector was a function of three things: (1) the internal impedance of the device; (2) the external capacitive reactance between the device and electrical ground or nearby electrical grounded conductors and equipment; and (3) the magnitude of the voltage being measured, that is, the voltage carried through the high voltage conductor. See for example, U.S. Pat. No. 6,753,678, which is incorporated herein in its entirety by reference, for further information about voltage detectors.
However, even when these three factors are accommodated in the voltage detector design, typical prior art voltage detectors are still not very accurate, ranging from up to 10% below to 50% above the true voltage. Thus there remains a need for a voltage detector having improved accuracy.